Vehicles often have various functions for improving a passenger's convenience, in addition to driving functions. However, the more functions a vehicle has, the more operating load a driver experiences. Excessive operating load deteriorates a driver's concentration on driving. Also, as a vehicle has more functions, a driver's difficulties in operating the vehicle might increase accordingly, such that a driver might be not able to properly use all functions the vehicle can perform.
In order to overcome the problem, studies into a vehicle-mounted input device for reducing a driver's operating load and difficulties have been conducted. A representative example of such a vehicle-mounted input device is a touch input device capable of detecting a driver's touch inputs. If a vehicle has such a touch input device, a driver would be able to easily control the vehicle by touching the touch input device without having to perform any complicated manipulations.